gms | German Medical Science

65th Annual Meeting of the German Society of Neurosurgery (DGNC)

German Society of Neurosurgery (DGNC)

11 - 14 May 2014, Dresden

Bone-anchored anular closure device following limited discectomy for primary lumbar disc herniation: Biomechanical testing, surgical technique, and preliminary clinical results

Meeting Abstract

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  • Nikolai G. Rainov - Department of Neurosurgery, Klinikum Augsburg, Augsburg, Germany
  • Jacob Einhorn - Barricaid Inc., Woburn, MA, USA
  • Volkmar Heidecke - Department of Neurosurgery, Klinikum Augsburg, Augsburg, Germany

Deutsche Gesellschaft für Neurochirurgie. 65. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). Dresden, 11.-14.05.2014. Düsseldorf: German Medical Science GMS Publishing House; 2014. DocMO.11.02

doi: 10.3205/14dgnc062, urn:nbn:de:0183-14dgnc0620

Published: May 13, 2014

© 2014 Rainov et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: Discectomy for lumbar disc herniation generally is effective in the early postoperative period, but decline in long-term outcome is common due to recurrent disc herniation and progressive degeneration. A novel bone-anchored anular closure device (ACD) was developed to address these failures. Pre-clinical biomechanical testing of the ACD device, surgical technique, and preliminary clinical results are presented.

Method: Biomechanical testing of the ACD device in the laboratory and a case series consisting of 15 patients (5 females, 10 males) with single-level posterolateral lumbar disc herniation are presented. Push-out, nucleus-pressure, and compression-shear failure mode testing with the ACD device were performed under both static and cyclic conditions. In the patients group, clinical data and radiologic imaging was analyzed.

Results: The ACD remained implanted during all laboratory tests, preventing nucleus extrusion and sufficiently supporting the posterior spinal column under a variety of static and cyclic testing. No intraoperative complications occurred in the patients group. Six-months follow-up was carried out in all patients. Improvements in low back and radicular leg pain VAS scores were observed. There were no cases of recurrent herniation, subsequent surgery, or postoperative complications. In all cases, the device was intact as shown on lateral X-ray of the lumber spine, with no evidence of subsidence or migration.

Conclusions: The ACD evaluated in this study has the mechanical properties necessary to remain implanted and intact while preventing nucleus extrusion and maintaining disc height under typical in vivo conditions and under the worst-case scenario of disc collapse. Device implantation was straightforward and without complications. Preliminary clinical results are encouraging, with improvements in pain and function and without complications. Additional randomized and prospective studies are necessary to assess the long-term capability of this ACD in minimizing recurrent disc herniation.